Heat and Poisson semigroups for Fourier-Neumann expansions

Given $\alpha > -1$, consider the second order differential operator in $(0,\infty)$, $$L_\alpha f \equiv (x^2 \frac{d^2}{dx^2} + (2\alpha+3)x \frac{d}{dx} + x^2 + (\alpha+1)^2)(f),$$ which appears in the theory of Bessel functions. The purpose of this paper is to develop the corresponding harmonic analysis taking $L_\alpha$ as the analogue to the classical Laplacian. Namely we study the boundedness properties of the heat and Poisson semigroups. These boundedness properties allow us to obtain some convergence results that can be used to solve the Cauchy problem for the corresponding heat and Poisson equations.Comment: 16 page

Luminosity segregation versus fractal scaling in the galaxy distribution

In this letter I present results from a correlation analysis of three galaxy redshift catalogs: the SSRS2, the CfA2 and the PSCz. I will focus on the observation that the amplitude of the two--point correlation function rises if the depth of the sample is increased. There are two competing explanations for this observation, one in terms of a fractal scaling, the other based on luminosity segregation. I will show that there is strong evidence that the observed growth is due to a luminosity dependent clustering of the galaxies.Comment: 7 pages, EPL in pres

On the Critical Behaviour of Heat Conducting Sphere out of Hydrostatic Equilibrium

We comment further on the behaviour of a heat conducting fluid when a characteristic parameter of the system approaches a critical value.Comment: 4 pages, emTex (LaTex 2.09), submitted to Classical and Quantum Gravity (Comments and Addenda

Gestión de clientes de servicios deportivos: un modelo de dinámica de sistemas

[ESP] Esta investigación propone un modelo general de gestión de clientes de servicios deportivos que pretende mejorar la dirección estratégica de los mismos. Para ello, se han integrado variables de la oferta y la demanda, en un planteamiento principalmente enfocado en la perspectiva de marketing. La dinámica de sistemas ha sido la metodología utilizada, con el fin de manejar la complejidad inherente al estudio de este tipo de fenómenos. Además, el modelo se presenta con un enfoque didáctico, en aras de facilitar su comprensión, describiendo las ecuaciones, aportando la sintaxis de programación, y dejando las puertas abiertas a la mejora y posible reformulación del mismo. [ENG] In this research a customer management model of sports services is formulated. This model may serve as a strategic tool that will allow managers to better understand the flow of customers in the sports centre. System dynamics has been used in order to deal with this complex task. The model is explained using a didactic approach. Finally, the equations and the program syntax are provided

Percepción del empleado y del cliente en servicios públicos deportivos

[ESP]Proponemos un modelo para medir las actitudes de los trabajadores de servicios deportivos públicos, con el fin de relacionar sus percepciones sobre su situación laboral y condiciones de trabajo con las actitudes de los consumidores. El modelo está concebido para ser utilizado con los trabajadores que interactúan con el cliente, ya que de su desempeño dependen buena parte de las evaluaciones que los consumidores realizan sobre el servicio. En el desarrollo de nuestra propuesta utilizamos un enfoque novedoso, basado en la modelización formativa y en el análisis de distribuciones de probabilidad. Así, ofrecemos una metodología de análisis que puede servir como guía para la dirección de recursos humanos, un área muy poco tratada en la investigación académica sobre servicios deportivos. [ENG] We propose a model for measuring the employee attitudes of public sports services, with the aim to establish a relationship between their perceptions of job conditions and the consumer attitudes toward the service provider. The model must be applied to customer-contact employees, because the performance of this type of employees is directly linked with the customer evaluations of the service. In the development of our proposal, we use a formative approach to measurement. In addition, the method for mapping both employee and customer perceptions is based on their probability distributions. Therefore, we offer a methodology of analysis that can serve as a guide to human resource management. The contribution of our study is valuable, because this field of research has been an under-researched area in the academic sports service literature

Natural Antibiotic Resistance and Contamination by Antibiotic Resistance Determinants: The Two Ages in the Evolution of Resistance to Antimicrobials

Work in our laboratory is supported by grants BIO2008-00090 from the Spanish Ministry of Science and Innovation and KBBE-227258 (BIOHYPO), HEALTH-F3-2011-282004 (EVOTAR), and HEALTH-F3-2010-241476 (PAR) from European Union.Peer reviewedPeer Reviewe